00:01
Of this equation right here, and we're told that we have a student who weighs 1 .25 grams of the sodium bicarbonate into a 50 mil beaker.
00:11
And then they're using 4 .6 milliliters of concentrated hydrochloric acid, and we're given this concentration of 12 moles per liter.
00:23
So that's 12 moles per liter.
00:26
And that's what they took of the hydrochloric acid.
00:29
So they have deserved effervescence due to the formation of carbon dioxide.
00:34
The water byproduct was removed and salt was left.
00:38
They dry and nacl remains.
00:46
So they have nacl.
00:48
Lastly, they took the weight of everything.
00:51
So the mass of the beaker is given as 28 .27 grams.
01:05
I want to make sure my microphone is on.
01:06
It is.
01:07
The mass excuse me, of my h -n -o -3, n -h -c -o -3, is, again, 1 .25 grams.
01:23
The residue mass of residue and the beaker, given is 29 .06 grams.
01:38
The volume of h -c -l was 4 .6 milliliters, and the molarity of h -c -l is 12 moles per liter, 12 molar.
01:56
Write the balanced chemically equation.
01:58
Okay, i already did that.
01:59
There's the balance chemical equation.
02:01
This is a.
02:02
B, let's switch colors.
02:04
B.
02:07
How many moles of n .a .h .o3? how many moles of the bicarbonate? so that's easy.
02:16
We'll take 1 .25 grams, and we'll multiply this by the molar mass of the sodium bicarbonate.
02:28
N .a.
02:29
H .c .o3 will be 84 .01 grams of the bicarbonate per mole.
02:46
Okay, getting my calculator.
02:51
That'll be 1 .25 divided by 84 .01.
02:57
Oops, i put a wrong number in there, divided by 84 .01.
03:04
And that is 0 .0149 grams of n -a -h -c -o -3.
03:15
There's my answer for b.
03:17
Hang on just a sec.
03:21
Can we do it in a couple minutes? i just want to finish this problem.
03:25
Okay, sorry about that.
03:27
Let me get back on there, and i'm going to jot down what this is without being rounded in case i need that later...